Yeti Crab

Quick Take

• Yeti crabs perform a rhythmic, dance-like motion for a surprisingly practical reason that has nothing to do with mating. See the claw-waving behavior →
• Despite the name, yeti crabs aren't actually crabs. Their true classification links them to a creature most people have seen before. Explore their true classification →
• Living near a hydrothermal vent is no safe haven. It is a lethal trap where drifting too far in either direction kills you. Learn about the vent habitat →
• One yeti crab species earned a Hollywood celebrity's nickname, and the resemblance is oddly hard to argue with. Meet the celebrity lookalike species →

Yeti crabs are a family of deep-sea decapod crustaceans with hairy arms and a white shell. The very first species (Kiwa hirsuta) of yeti crab was only discovered in 2005 on a hydrothermal vent along the Pacific-Antarctic Ridge, approximately 900 miles south of Easter Island. Despite its small eyes and poor eyesight, the yeti crab has several unique adaptations to survive in the harsh, cold, and desolate deep-seafloor environment. Because they can only be reached by deep-sea submarines, much about them remains poorly understood.

3 Incredible Yeti Crab Facts

• Yeti crabs pile on top of each other to stay warm near hydrothermal vents. One scientist counted some 700 crabs per square meter.
• A genetic analysis suggests that the yeti crab family first evolved some 30 million years ago when their ancestors first colonized hydrothermal vent biomes.
• Because it lives deep in the water, the yeti crab does not need color pigments, making it appear white or gray.

Classification and Scientific Name

The yeti crab is classified in the family Kiwaidae and genus Kiwa. It is named after the god of shellfish in Polynesian mythology. The yeti is not considered to be a member of the “true crabs,” but rather a closely related group called the squat lobsters, which includes the hermit crabs. More widely, they belong to the decapod order.

Species

There are currently four recognized species of yeti crabs:

• Kiwa hirsuta: This is the first species discovered back in 2005 by a group of researchers from the Monterey Bay Aquarium Research Institute. The crab was so different from any other decapod that it warranted an entirely separate family. The name hirsuta is actually a Latin word meaning “hairy.”
• Kiwa puravida: A second species was discovered in 2006 near the waters of Costa Rica. It has the same hairy claws as Kiwa hirsuta.
• Kiwa tyleri: First discovered in 2010, this species resides in the East Scotia Ridge, near Antarctica. It was jokingly named the Hoff crab because its hairy chest resembled the actor David Hasselhoff. The conditions of its environment are extremely cold.
• Kiwa araonae: This species was first discovered in 2013 near the Australian-Antarctic Ridge. While it does have long claws, it also lacks long, bristly hair.

Appearance

The yeti crab is characterized by a generally crab-like shape (the hard shell, the long appendages, and the big claws), but it also looks very much like the mythical snowman for which it was named. The defining features are the compact, all-white body, measuring about 15 cm (5.9 inches) long, and the long, bristly claws that enable them to harvest bacteria.

Some have hairy chests in addition to or in place of the hairy claws. Because of its highly reduced eyes, it is thought to be completely or mostly blind.

Distribution, Population, and Habitat

The yeti crab is largely endemic to the cold habitats of the southern Pacific Ocean region, adjoining the waters of the Antarctic. The hydrothermal vents near which they live are essentially cracks in the deep-sea floor where mineral-rich scalding hot water escapes from the surface of the earth.

While they are highly adapted to their habitat, survival requires a very careful balance. If they stray too far from the vents, they can freeze to death in the frigid sea. However, if they wander too closely, they can overheat and die.

Because there is not enough data available about them, the IUCN Red List has never assessed the conservation status of any of the four known species.

Predators and Prey

Life near the hydrothermal vent is different from almost anywhere else on the planet. Organisms cannot rely on sunlight to capture energy, so they convert chemical energy directly from the vents. The yeti crab’s role in this complex ecosystem is not yet fully understood, but we do know that it feeds on the bacteria flowing from the vents.

What eats the yeti crab?

The yeti crab does not seem to have many predators in its natural environment. It is thought that some deep-sea octopuses and fish may find them edible.

What does the yeti crab eat?

The entire diet of these crabs revolves around bacteria. By waving their hairy claws through the plumes of oxygen, methane, and hydrogen sulfide emanating from the vents, they harvest the bacteria growing there. To the human eye, this movement resembles a rhythmic dance.

Reproduction and Lifespan

The reproductive behavior and lifespan of these crabs remain a complete mystery. It is believed that the hydrothermal vents are too warm for their larvae to develop, so the female probably lays her eggs in the colder surrounding waters. Very few other facts are known.

Fishing and Cooking

Because of their remote environment, these crabs are not used in cooking or fishing. Since no one has tasted them, it is unknown whether they are edible.